Permanent TSB has drastically ramped up efforts to purge its balance sheet of non-performing loans, launching a blockbuster loan portfolio sale worth close to €4bn, according to sources.

The Irish Independent understands that Project Glas, the sales process it launched on Tuesday, is divided into two separate portfolios, Project Tibet and Project Nepal.

Sources said the former is comprised of mortgages attached to principal home dwellers with a gross value of close to €3bn, marking one of the largest sales of homes ever undertaken in the State. It is understood Bank of Ireland has displayed interest in the assets.

Project Nepal is formed mostly of buy-to-let mortgages and has a gross value of close to €1bn.

A spokesperson for PTSB declined to comment.

However the lender has flagged its intention to drastically reduce its non-performing loan exposure, which currently accounts for 28pc of the entire loan book, the highest among the Irish lenders.

It is understood both portfolio have attracted a swarm of local and international buyers with private equity funds and distressed debt players among the possible suitors.